Surgical procedures often require the creation of a surgical exposure to allow a surgeon to reach deeper regions of the body. The surgical exposure is usually started with an incision of a suitable depth. Surgical instruments known as retractors are then inserted into the incision and used to pull back skin, muscle and other soft tissue to permit access to the desired area.
A typical retractor is made up of a retractor body attached to one or more retractor blades. Retractor blades are smooth, thin plates with dull edges that are inserted into the incision to pull back the tissue. Retractor blades come in many different sizes depending on the particular application and physical characteristics of the patient. Retractor blades may be slightly curved or completely flat and may have end prongs of various configurations to make it easier to pull back tissue. The retractor blades can be attached to a wide variety of retractor bodies, such as for hand-held and self-retaining retractors.
Hand-held retractors are made up of a simple grip attached to a retractor blade. The retractor blade may be fixed or interchangeable. The retractor blade is inserted into the incision and then the grip is used to pull back the blade to create the surgical exposure. The grip may be attached at an angle to the retractor blade to make it easier to pull back on the blade. Hand-held retractors must be held in place by hand in order to maintain the surgical exposure.
Self-retaining retractors have specialized retractor bodies that allow them to maintain a surgical exposure without needing to be held in place by hand. Two common self-retaining retractors are longitudinal retractors and transverse retractors.
Longitudinal retractors have a retractor body made up of two seesawing arms with a pair of opposed retractor blades on their respective ends. The retractor body typically has a ratcheting mechanism to lock apart the two opposed retractor blades and hold them in place. This maintains the surgical exposure without the need for the retractor to be held in place by hand. The two arms may be hinged to facilitate access to the retraction site. The retractor blades may be either fixed or interchangeable.
Transverse retractors have a retractor body made up of a transverse rack with a fixed arm and a sliding arm. The fixed arm and sliding arm have opposed retractor blades on their respective ends. The sliding arm typically has a turnkey that operates a ratcheting mechanism, which ratchets the sliding arm away from the fixed arm and locks apart the retractor blades. The two arms may be hinged to facilitate access to the retraction site. The retractor blades may be either fixed or interchangeable.
For interchangeable retractor blades, there are several connector designs for allowing the retractor blades to be interchangeably attached to the retractor body. One connector is the top-loading ball snap design, which resembles the mechanism found in common ball-and-socket wrench kits.
The ball snap design uses a top-loading socket which fits over the top of the ball snap. The retractor blades used with the ball snap design typically have a top end bent at a right angle to create a perpendicular section on which the ball snap is mounted.
The ball snap design allows the retractor blades to positively lock into the top-loading socket. This allows the entire retractor to be assembled and handed to the surgeon without the risk of the retractor blades falling off. It also permits the entire retractor to be repositioned in the incision without the risk of the retractor blades becoming detached from the retractor body.
However, many surgeons prefer to position the retractor blades first before attaching the retractor body. Positioning the retractor blades first makes it much easier for the surgeon to create a precise surgical exposure before attaching the retractor body. Pre-positioning of the retractor blades also facilitates the selection of the proper retractor blade length and width.
With the ball snap design, the surgeon must line up the sockets in the retractor body over the tops of the ball snaps before snapping the retractor blades in place. This is a difficult process, as the retractor body arms must be aligned over the ball snaps precisely in order to attach the retractor blades. This alignment process is complicated by the hinged arms and ratcheting mechanisms often found in retractor bodies.
Current side-loading designs attempt to address these problems by making it easier to load the retractor blades into the retractor body after the surgeon has pre-positioned the retractor blades. Current side-loading designs use a post or rail that allow the retractor blades to be loaded from the side. This allows the retractor body to be placed between the retractor blades and then simply opened up to engage the retractor blades from the side.
However, current side-loading designs do not allow the retractor blades to be positively locked into the retractor body. This means the entire retractor cannot be assembled and then handed to a surgeon without the risk of the retractor blades falling off. The retractor blades are held in place only by the opposing force of the retracted tissue and may become detached from the retractor body if the surgeon tries to reposition the retractor blades inside the incision. Furthermore, current side-loading designs often misalign, resulting in a poor connection between the retractor blade and the retractor body.
What is needed is a surgical retractor with interchangeable retractor blades, where the retractor body can accept the retractor blades easily without the need for precise alignment and where the retractor blades can be positively locked into the retractor body.